Sweating at night can be caused by high ambient temperature, calcium deficiency, and hyperthyroidism. 1. High ambient temperature: If the ambient temperature is too high at night and the parents are afraid that the child will get cold and wear too much clothing, the child will sweat more when sleeping. 2. Calcium deficiency: when a child is deficient in calcium, the blood calcium concentration will decrease and the sweat glands will secrete a lot of sweat, which will make the child sweaty at night. 3. Hyperthyroidism: if a child suffers from hyperthyroidism, the excessive secretion of thyroid hormones in the blood may lead to increased nerve excitability, hyperbasal metabolic rate, and increased thermogenesis, which will lead to sweating. There may be other reasons for your child’s night sweating, so it is recommended that you go to the hospital in time for a complete examination to determine the cause of the problem, and then give targeted treatment under the guidance of the doctor.